Hey folks, I'm saving up to hop up my 64 skylark. Has 455/th400/ 10 bolt 3.08 posi. 70 model engine and heads, not a stage 1. Car runs fine as is but is pretty lame. It will burn the tires, but otherwise is just plain Jane. I thought about the blasphemous bbc, but $10g here, $3g, there, plus the pita of installing it , yuck. The 455 is already there plus all brackets, and other little pests. Anyway, I'd like to up the scary on the 455 quite a bit, well no more than a 2400 stall torque converter worth of scary. Assuming the block hasn't been bored to its last rebuild already, how would you guys go about it? I'll tell you, it has a performer intake and with drop base cleaner, just barely clears the hood, any taller, I'm cutting a hole, which I'm not opposed to, but would like to keep the cowl scoop as low as possible. Plus, I will spring for tbi injection, beyond that, would like the parts side for motor and transmission $10,000 or less. Or can all this be summed up with a call to TAPerformance,lol.
I would start with timing and correct carb. Read Larry's power timing thread. Worn timing chain? Lots of peripherals you can iron out before spending the big bucks.
Aluminum heads with entry level porting, 10:1 compression and a cam with 230* of intake duration at .050. That will make 500+ HP and even more torque.
Yes as long as the bottom end and bearing clearances are good and you have good oil pressure. Just keep the RPM at or below 5700. Headers help a lot, but not 100% necessary. Head flow is where the power is.
Oh, a cam in the 230 duration area probably won't make enough vacuum for brakes, correct? Just wondering if I needed to use a 6.0 power stroke vac pump and vac can for them.
My cam is 230/238, 112 LSA. It's a roller cam, but it makes 15" in Park at 900 RPM, 12" in gear. No problem at all with power brakes.
I spoke with Tim at TA, he said for a good street combo, use their stage 1 heads, and 290-94h cam, said 2000 stall would be fine with this combo. Not knowing squat about the engine, it will come out for a freshening up(bearings, seals, oil pump, etc..) at a bare minimum. Would rather do it on my terms vs it laying down on me. I asked about Pistons to up the compression, said they should have what I need. He said to use their headers, I'd need to use their frame pads to even stand a chance, but manifolds must not be too horrible because I brought the subject up. Also acted like the performer intake was fine as well. Seems these really don't need the help like Chevys do. That's good know about the brakes, guess the wider Lsa helps in the vacuum department.
If you buy pistons from TA, make sure they sell you pistons with the better compression distance so that you can get the pistons close to or at zero deck. You want at least 10:1 static compression with aluminum heads. Don’t buy pistons that are going to end up .040-.050 in the hole. Those are the commonly available pistons. Pay a little more for custom. http://www.trishieldperformance.com/470--what-and-why-.html From the above link, " Buick 455 pistons in the aftermarket today all are more or less "Blueprint spec" pistons. When the Buick engineers designed the engine, the created a set of specifications for the engine, one of which was compression distance on the piston. Virtually all Aftermarket pistons on the market now are based on that spec. The problem with that is the fact that the stock piston was designed to be .030 to .040 below the deck surface of the block. This allowed for production variance in sizing, on everything from the crank, rods , pistons ... to the block itself. Pistons sticking out of the bores would be the death on the assembly line, so that could not happen. Hence the very conservative CD of the stock piston. Nearly all aftermarket pistons available for the 455 Buick, have a compression distance of 1.975 to 1.985. Where we end up: If we do the math, we see that to reach 10.570, which is the deck height of the 455 Buick, we need a piston that has a compression distance of 2.02. If we were working with an NOS block, we would want a piston with a CD of 2.02. In normal rebuild situations, we have found that it takes a .020 cut to perfectly square and clean up the deck of the block, so with stock crank and rods, we would want a piston with a 2" CD in a rebuild situation, to produce a zero deck clearance. What what happens when you use "inexpensive" pistons To use previously available forged pistons, and achieve the preferred zero deck clearance, it is common to have to machine .040-.055 off the decks. I did this many times. And when you cut the decks this much, even with new heads, the intake does not fit anymore. As the decks go down toward the crank centerline at 45*, the "V" gets narrower. So now we are cutting the intake, or intake side of the heads to make it all fit together. More than a few guys just slotted the bolt holes to physically get the intake on. Not ideal for sure, and doing it the "right way" with all the milling, is just wasted time and money. All because we don't have the correct piston available. Most machinists I have worked with charge a double charge for decking more than .030. Why you should care about this Your new Performance engine is the most efficient, the least prone to detonation, and the most powerful when the pistons are level with the surface of the cylinder block. This is know as "zero deck clearance", and is universally accepted in the performance aftermarket to be the most desirable situation. Why would you settle for less? We can accommodate special requirements for both CD and dish volume if the situation required it, for a small extra fee. We also can build zero deck pistons for stock rod/crank 400/430/455 Buicks, in any bore size required, without the full custom price."
X2 on what Larry said, but don't forget another important factor why go to custom pistons vs of the shelf stuff. It is ring package........and not the big heavy standard ring size the shelf pistons use.
He did mention about distance and I believe he said Pistons were available to get to zero or at least very close. Don't quote me on it though. Just gotta save up a couple more thousand and hope it's enough. Don't want visa owning a single bolt if I can help it.
Wouldn't just using .025 longer rods enable you to use the standard pistons? I ask because I have a brand new set of forged speed pro pistons sitting here on my shelf, and I would rather not re-purchase something unless absolutely needed.
I kinda dig using the bbc rods deal I saw on trishield's website. Whole lot more selection. But, if mine are fine, why not reuse em. Going down another avenue, I wonder if the stage 2 tall heads would help with header clearance? Or would that just be 1 fix but create 5 other problems?
Getting replacement aftermarket rods does eliminate the hassle of trying to balance the goofy OEM "center-of-mass" rods. Another option is to offset-grind the crank. You gain piston height and a few cubes at the same time, as long as the bottom of the piston clears the crank counterweights.
Hahaha, going down that rabbit hole? What you need to do is make a list on what you want to do and what parts you need and Budget......STICK WITH THAT LIST/BUDGET. Trust me. If not then you are out 5 grand. I have my 455 (shot block assembled) on an engine stand that has been sitting for years with everything else to put it together but ran out of money to do the heads. now I have no time to do anything.
